Evaluate the sustainability of multiple fungicide applications to corn

Commodities

Practices

Unnecessary fungicide applications affect our ability to
sustainably manage crop diseases. They provide opportunity for
fungal pathogens to develop fungicide resistance due to routine
chemical exposures. We need to conserve our use of fungicides
now, so that products are available in the future as disease
pressure is predicted to increase with a changing climate. Loss
of fungicides will increase our reliance on techniques like
tillage to bury diseased crop residue.

The recent emergence of two corn diseases in the north central US
has led to even more concern about stewardship of
fungicides.  Tar spot and southern rust of corn can reduce
yields by 45 to 50 bushels per acre in certain conditions. In
2023, some farmers in northwest Missouri chose to make three
fungicide applications to manage tar spot. Success of those
applications in protecting yield remains unknown. The general
lack of information to assist these farmers and others in making
application decisions can be addressed through on-farm strip
trials.

The proposed partnership will allow University of Missouri
Extension Specialists and Missouri farmers to compare single and
multiple fungicide applications to corn.  Reducing
unnecessary fungicide use is an important component of
sustainable integrated disease management.

We plan to carry out on-farm strip trials to provide information
on economic and sustainability benefits (and costs) of multiple
fungicide applications to corn. We will utilize the following
types of data for this analysis:

• Agronomic input data like seeding rate, row spacing,
  irrigation, total number of active ingredients in products,
  growth stage at application
• Economic input costs for products and application
• Environmental data, such as topography and weather
• Yield data

Findings generated from this study will be applicable to farmers
and agriculture professionals in the north central region and to
technical audiences working to find sustainable disease
management solutions.